Checking Pcor Setting On A Test Stand; Adjusting The Pcor Setting - Danfoss 51 Series Service Manual

Service Manual
Adjustments
Series 51 Two Position Controls Service Manual
2. Install a 600 bar [10000 psi] gauge at port M3 to read minimum servo pressure.
3. Safely prevent the motor shaft from moving by:
•
applying the park brake, apply an extreme load, or
•
positioning the machine against an immovable object, or
•
use other means to hold the machine.
4. Start the prime mover. Operate at medium speed.
5. Stroke the pump very slowly to gradually increase the system pressure.
An alternate method to slowly increase the system pressure is to use the pump's pressure limiter (PL)
valve. Lower the PL setting below the PCOR setting. Stroke the pump to about one-fourth
displacement. Raise the PL setting slowly to increase system pressure until pressure at the M3 port
drops down. System pressure at this point is the PCOR setting. Adjust the PL back to its proper setting
after checking the PCOR setting.
6. Increase system pressure until pressure at port M3 drops down, system pressure at this point is the
PCOR setting.

Checking PCOR Setting on a Test Stand

Increase system pressure until the system flow begins to increase (+8 l/min [2 US gal/min]). System
pressure at this point is the PCOR setting.
System pressure may increase rapidly when flow increases.

Adjusting the PCOR Setting

For PCOR valves mounted on a multiblock, use a 1-1/16 inch wrench to loosen the lock nut on the
adjusting screw. Using a large screw driver or a 13 mm wrench turn the adjusting screw clockwise to
increase pressure setting or counter clockwise to decrease pressure setting. One turn of the adjusting
screw changes the setting approximately 69 bar [1000 psi].
For controls using the threshold adjusting screw for PCOR adjustment, use a 10 mm wrench to loosen the
locknut. Using a 3 mm wrench turn the adjusting screw clockwise to increase pressure or counter
clockwise to decrease pressure setting. One turn of the adjusting screw changes the setting
approximately 55 bar [800 psi].
11009442 • Rev CA • January 2015 17